The present disclosure relates to a waste toner transporting device and to an image forming apparatus incorporating the waste toner transporting device. More particularly, the present disclosure relates to a waste toner transporting device that includes a waste toner passing passage through which waste toner passes and that includes a suction passage for suction of suspended toner inside a developing device, and to an image forming apparatus incorporating such a waste toner transporting device.
In one common process in image forming apparatuses adopting electrophotography, such as copiers, printers, and facsimile machines, powder developer is mainly used, an electrostatic latent image formed on a photosensitive drum (image carrying member) is made visible by use of a developing device, and the visible image (toner image) is transferred to a recording medium directly or via an intermediate transfer member (image carrying member) and is then fixed. Toner left unused on the surface of the image carrying member is removed by a cleaning device and is discharged out of the cleaning device by a discharging mechanism such as a toner discharging screw to be stored in a waste toner collection container.
On the other hand, when toner is fed from the developing device to the photosensitive drum, part of toner may be scattered and leak out through an opening in the developing device opposite the photosensitive drum, contaminating the inside of the image forming apparatus. As a solution, a configuration has been proposed in which a duct is connected to a developing device to collect toner (suspended toner) scattered in the vicinity of an opening in the developing device by use of a suction device.
For example, an image forming apparatus is known in which a dust collection portion is provided to which ducts arranged in upper parts of developing devices are connected via a confluence duct. In the dust collection portion, an exhaust fan is arranged, and between the exhaust fan and the confluence duct, a filter is arranged. The air discharged from the developing devices through air outflow passages into the ducts meets in the confluence duct, and is discharged from the dust collection portion out of the main body of the image forming apparatus.